title: Prognostic value of somatostatin receptor-2 positivitiy in gastroenteropancreatic neuroendocrine tumors in reference to known prognostic factors.
abstract: OBJECTIVE
  Identification of the predictive factors for the prognosis of gastroenteropancreatic neuroendocrine tumors is important but rather challenging due to the rarity of the condition. This study aimed to examine the association between somatostatin receptor-2 positivity and known prognostic factors for gastroenteropancreatic neuroendocrine tumor to identify the value of somatostatin receptor-2 positivity itself as a predictive factor for prognosis.
  
  
  METHODS
  Records of 41 gastroenteropancreatic neuroendocrine tumor patients (24 females, 17 males) were retrospectively reviewed. The relations between somatostatin receptor-2 positivity and known prognostic factors including tumor stage, Ki-67 positivity, vascular or perineural invasion, lymph node metastasis, presence of necrosis, and soft tissue extension were analyzed.
  
  
  RESULTS
  Sixty percent of the patients had histologically confirmed somatostatin receptor-2 positivity with 45% exhibiting focal and 15% showing diffuse staining characteristic. No significant relation was found between somatostatin receptor-2 positivity and any of the known prognostic factors for gastroenteropancreatic neuroendocrine tumor: versus stage, p=0.67; vs. lymph node metastasis, p=0.51; vs. vascular invasion, p=0.11; vs. extension to surrounding soft tissue, p=0.54; vs. necrosis, p=0.23; vs. lymphatic invasion, p=0.25; and vs. perineural invasion, p=0.42.
  
  
  CONCLUSIONS
  Somatostatin receptor-2 positivity, either focal or diffuse, does not seem to predict prognosis in gastroenteropancreatic neuroendocrine tumors. However, growing evidence supports the benefits of somatostatin analogues as adjunctive treatment in this group of patients.
authors.affiliation: Ege University School of Medicine, Department of General Surgery, İzmir, Turkey. lyeniay@yahoo.com
authors.forename: Levent
authors.initials: L
authors.lastname: Yenıay
authors.forename: Barış
authors.initials: B
authors.lastname: Gürcü
authors.forename: Ömer
authors.initials: Ö
authors.lastname: Ünalp
authors.forename: Funda
authors.initials: F
authors.lastname: Yilmaz
authors.forename: Deniz
authors.initials: D
authors.lastname: Nart
authors.forename: Murat
authors.initials: M
authors.lastname: Sözbılen
authors.forename: Ahmet
authors.initials: A
authors.lastname: Çoker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000453:epidemiology / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000453:epidemiology / Q000378:metabolism* / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000453:epidemiology / Q000378:metabolism* / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D014408:Biomarkers, Tumor; D017481:Receptors, Somatostatin; C574734:SSTR2 protein, human